Showman Trump defensive in final presidential debate

Americans will vote for a new president on November 8 [Carlos Barria/Reuters]

Donald Trump made his fortune in business. That fortune brought his fame. And he solidified his fame through a reality show. It was a successful reality show. He knows how to keep people watching, keep them hanging on for the dramatic final reveal.

He seems to believe he can do the same in the US presidential election.

US election 2016: Trump slams the media for 'bias'

After weeks of claiming the election is rigged and that an international conspiracy aims to deprive him of the White House, he was asked in the third presidential debate in Las Vegas if he would accept the final result.

He said he would "keep people in suspense". It was a bad moment for Donald Trump and I'll explain why in a moment.

The third debate was perhaps his most focused performance yet, but it wasn't consistent.

For the first 30 minutes, he made solid points, drew a clear difference between himself and Hillary Clinton.

The way he talked about the appointment of Supreme Court Justices would give doubtful Republicans the chance to hold their nose and cast their vote for him

'Such a nasty woman'

But then the game plan seemed to disappear. He became short tempered and sarcastic. He interrupted his opponent regularly, and for a man who said there was no one who had more respect for women, he responded to a curt aside from Clinton by saying "such a nasty woman". It drew a sharp intake of breath from many following proceedings in the media filing centre.

Trump needed a big win to reverse some of the losses in the polls over the past two weeks. This wasn't it.

His campaign immediately claimed a win but it was at best, a draw. And with no clear winner, that made Trump the loser.

To cement her place as the candidate most likely to succeed, the Democratic nominee had to do no harm, make no major mistakes and navigate her way through the expected Trump attacks.

She managed exactly that. She turned a Trump assault on her 30 years in public life, highlighting her role as a professional politician, into an opportunity to attack his lack of experience.

"On the day I was in the situation room monitoring the raid that brought Osama bin Laden to justice, he was hosting the Celebrity Apprentice," she quipped.

And what could have been a damaging attack on some of the leaked campaign emails, she pivoted to blame Russia and claim Trump would be a puppet of Russian President Vladimir Putin.

Uncomfortable moments

Her most uncomfortable moment was when Trump questionined the work of the Clinton Foundation and the reputation of some its donors. She turned that around to attack Donald Trump, his foundation, its decisions and donations it had made.

After this debate she is a step closer to the White House.

So why was the discussion about accepting the result a bad moment for Trump?

He made some good points against Clinton, and raised questions that have to be answered. But the American media will be dominated for the next 24-48 hours over his refusal to say whether he'll accept the decision of the American people. It's unprecedented. A cliffhanger which may appeal to the showman in him, but which the country doesn't need, especially after a campaign which has been brutal, angry and divisive.

His campaign has been trying to explain what he meant, how everyone should have worries about a fair election and how he was perhaps misinterpreted.

But in politics, like sport, if you're on the defence, you're not on the offence. With 20 days to go, and a lot of ground to make up, that's somewhere the Trump campaign doesn't need to be.